Pusher guide wire and delivery system comprising the same

Abstract

A pusher guide wire and a delivery system can smoothly pass through the inside of even a curved blood vessel without causing excessive burden to a stent, a catheter, and the like. A pusher guide wire has a tubular member capable of moving in a radial direction relative to a core shaft of the pusher guide wire. When the pusher guide wire is used together with a stent in a delivery system, the tubular member makes contact with the stent in an appropriate manner when passing through the inside of a curved blood vessel. The stent may include a proximal end engagement portion provided at a proximal end of the stent. When the stent is placed so that the proximal end engagement portion engages with the pusher guide wire, the stent can be pulled back inside the catheter by pulling the pusher guide wire in the proximal direction.

What is claimed is: 
     
       1. A delivery system to be inserted into a catheter, the delivery system comprising:
 a pusher guide wire for delivering a stent to a target site, the pusher guide wire comprising:
 a core shaft; 
 a first coil body covering the core shaft and fixed to the core shaft; 
 a second coil body covering the core shaft and fixed to the core shaft at a position proximal to the first coil body, the first coil body and the second coil body being spaced apart from each other in an axial direction of the pusher guide wire; and 
 a tubular member disposed between the first coil body and the second coil body such that the core shaft extends through an inside of the tubular member, 
 wherein: 
 the tubular member is not fixed to the core shaft and is capable of moving in a radial direction relative to the core shaft, and 
 the second coil body has a tapered portion with an outer diameter that increases toward a proximal end of the pusher guide wire; and 
 
 a stent to be delivered by the pusher guide wire, the stent comprising:
 a proximal end portion; and 
 a proximal end engagement portion that protrudes toward an outer periphery of the core shaft, 
 wherein when the stent is stored within the catheter: 
 an inner diameter of the stent at the proximal end engagement portion is smaller than a maximum outer diameter of the tapered portion, 
 the proximal end engagement portion is located between the tapered portion and the tubular member in an axial direction of the core shaft, and 
 a distal end of the stent is located distal to the tubular member. 
 
 
     
     
       2. The delivery system according to  claim 1 , wherein:
 an inner diameter of the tubular member is smaller than each of an outer diameter of the first coil body and an outer diameter of the second coil body; and 
 an outer diameter of the tubular member is larger than each of the outer diameter of the first coil body and the outer diameter of the second coil body. 
 
     
     
       3. The delivery system according to  claim 1 , wherein the tubular member is formed of a radiopaque material. 
     
     
       4. The delivery system according to  claim 2 , wherein the tubular member is formed of a radiopaque material. 
     
     
       5. A delivery system to be inserted into a catheter, the delivery system comprising:
 a pusher guide wire for delivering a stent to a target site, the pusher guide wire comprising:
 a core shaft; 
 a first coil body covering the core shaft and fixed to the core shaft; 
 a second coil body covering the core shaft and fixed to the core shaft at a position proximal to the first coil body, the first coil body and the second coil body being spaced apart from each other in an axial direction of the pusher guide wire; and 
 a tubular member disposed between the first coil body and the second coil body such that the core shaft extends through an inside of the tubular member, 
 wherein the tubular member is not fixed to the core shaft and is capable of moving in a radial direction relative to the core shaft; and 
 
 a stent to be delivered by the pusher guide wire, the stent comprising:
 a distal end portion; and 
 a distal end engagement portion that protrudes toward an outer periphery of the core shaft, 
 wherein when the stent is stored within the catheter: 
 an inner diameter of the stent at the distal end engagement portion is smaller than an outer diameter of a distal end of the tubular member, and 
 the distal end engagement portion is located between the first coil body and the tubular member in an axial direction of the core shaft. 
 
 
     
     
       6. The delivery system according to  claim 5 , wherein:
 an inner diameter of the tubular member is smaller than each of an outer diameter of the first coil body and an outer diameter of the second coil body; and 
 an outer diameter of the tubular member is larger than each of the outer diameter of the first coil body and the outer diameter of the second coil body. 
 
     
     
       7. The delivery system according to  claim 6 , wherein the second coil body has a tapered portion with an outer diameter that increases toward a proximal end of the pusher guide wire. 
     
     
       8. The delivery system according to  claim 5 , wherein the second coil body has a tapered portion with an outer diameter that increases toward a proximal end of the pusher guide wire. 
     
     
       9. The delivery system according to  claim 5 , wherein the tubular member is formed of a radiopaque material.